Our aim is to characterize, breed and distribute to qualified investigators a series of mutant mice or tissus from such mice, as a stimulus to the experimental study of disease models relevant to the goal of increasing the understanding and therapeutic control of human ophthalmological disorders. The majority of the relevant mutations and inbred lines are already in hand, ready to be expanded for use by others. These include four major models of diseases in the retinitis pigmentosa class, named Retinal degeneration, Nervous, Purkinje cell degeneration, and Retinal degeneration slow. The middle two of these, like several of the human diseases, involve degeneration of photoreceptor cells and selected classes of neurons elsewhere in the nervous system. Control of genetic background and use of multiple alleles will extend the analytical opportunities considerably. Additional models of congenital stationary night blindness, aberrant optic axon growth (as in human albinos), and defects of eye movement coordination reflexeswill be propagated, and new relevant mutations will be added as they are developed. An administrative mechanism will be established to foster optimal standards of animal care and genetic quality control, computerized pedigree recording, and (in close cooperation with National Eye Institute administration) evaluation and prioritization of outside requests for breeding stock, affected animals and genetically-appropriate controls, frozen or fixed tissues, and nucleic acid and protein extracts.